/**
 * View-frustum culling via 6 planes extracted from a view-projection matrix.
 *
 * Griham–Hartmann method: each frustum plane is a linear combination of
 * VP matrix rows. Planes point inward (positive half-space = inside frustum).
 */
import type { Mat4Type } from '@certe/atmos-math';
import type { BoundingSphere } from './bounds.js';
/** 6 planes × 4 coefficients (a, b, c, d) where ax+by+cz+d >= 0 is inside. */
export type FrustumPlanes = Float32Array;
/** Extracts 6 frustum planes from a column-major VP matrix. */
export declare function extractFrustumPlanes(out: FrustumPlanes, vp: Mat4Type): FrustumPlanes;
/** Returns true if the sphere is at least partially inside the frustum. */
export declare function isSphereInFrustum(planes: FrustumPlanes, sphere: BoundingSphere): boolean;
//# sourceMappingURL=frustum.d.ts.map